The invention relates to solenoid actuated control valves and more particularly to a control valve having an interchangeable valve element which enables the valve to operate either as a normally opened or a normally closed valve.
The present invention describes a control valve that can be used with small modifications in many applications. Among the features of the present invention are a modifiable flow area that can be easily changed by adjusting the stroke of the solenoid valve or a corresponding annular flow area. In addition with minor modifications the present invention is capable of operating as a normally opened valve or as a normally closed valve. A basic concept employed in the present invention is to separate the solenoid function from the valve function. This enables the valve element to be changed without changes to the solenoid. In addition if a common solenoid is used with many valve elements a corresponding decrease in the cost of production of the solenoid control valve is achieved through the economy of large volumes.
Accordingly the present invention comprises: a solenoid control valve having: a stator adapted to receive an electric activation signal and to generate a magnetic field upon activation and a valve body adapted to engage a coacting surface of said stator having: an inwardly extending first bore; an inwardly extending stepped bore, an upraised boss extending axially upward from the bottom of the narrow portion of said stepped bore, the boss including an axially extending hole communicating the first bore with the said stepped bore. The valve further includes an armature comprising a ferro-magnetic first portion and a piston extending therefrom, the first portion is reciprocally situated within the first bore, and the piston is reciprocally received and extends through the hole in the boss. A spring retainer is attached to and is movable with that portion of the piston extending beyond the boss. The spring is received within the volume between the walls of the narrow portion of the stepped bore and the exterior walls of the boss for outwardly biasing the spring retainer and the armature. The control valve includes a reversible valve means including a valve seat adapted to be received within the stepped bore of the valve body and at least one flow passage adapted to receive fluid and further includes a movable valve closure element such that when the valve seat is received in one orientation the solenoid valve is of the normally open variety and when inserted in an opposite orientation the solenoid valve is of the normally closed variety.